Endoscopic and minimally invasive medical procedures, such as laparoscopy, have become widely accepted for surgery and illness diagnosis. This is due to reduced trauma to the patient and reduced hospitalization time. Other techniques exist for creating a working space within the abdominal cavity, but the vast majority of laparoscopic operations worldwide are performed using the technique of pneumoperitoneum.
At the beginning of all laparoscopic cases, a small incision is made, followed by a small (1 cm) hole in the remaining layers of the abdominal wall so as to gain access to the peritoneal cavity. An alternative method of gaining access to the peritoneal cavity is to insert a small needle through the abdominal wall and to instill CO2 through this needle into the peritoneal cavity. The peritoneal cavity is usually inflated to a pressure of about 14 cm H2O. The pressure of the pneumoperitoneum must be maintained at all times during the operation. An automatic insufflation pump keeps CO2 flowing to maintain a preset working pressure. If pressure is lost, the working space collapses, nothing can be seen, via a video system, and the operation comes to a halt. This working pressure must be maintained despite the need to introduce and remove cameras, instrumentation, and the like through the abdominal wall during the operation.
The solution to this problem has been the development of laparoscopic ports. These devices, in their simplest form, consist of tubes which penetrate the abdominal wall to provide a path for the introduction, removal, and exchange of instruments, etc. Prior art ports must be inserted through the abdominal wall. This is usually done by the use of a sharp spike, known in the art as a “trocar,” which is positioned within the lumen of the port, and inserted into the abdominal wall so as to pierce it. The trocar is then removed from the lumen of the port. Prior art ports also incorporate some type of valve or seal mechanism to create an airtight seal around an instrument as it is slid through the port and into the abdominal cavity. This is to prevent leakage from the pressurized pneumoperitoneum. The seals must be efficient, as even seemingly small leaks can exceed the maximum insufflation rate of CO2 pump.
Most laparoscopic operations use pneumoperitoneum and a separate port of each instrument. For example, for gallbladder removal (laparoscopic cholecystectomy), two instruments are required for retraction, while another is required for dissection, then often requiring three ports. An additional port is required for the video camera bringing the total number of ports required to four for performing a laparoscopic cholecystectomy. Instruments may be exchanged through any of the ports at any time. Other common laparoscopic operations including hernia repair, appendectomy, stomach surgery, and gynecologic surgery require from three to five ports for performing each operation. Such procedures commonly involve performing a number of individual acts or functions within the anatomical cavity including grasping, cutting, coagulating, irrigating, aspirating, puncturing, injecting, dissecting, cauterizing, ligating, suturing, illuminating, visualizing and/or collection specimens for biopsy. Endoscopic instruments are often designed to perform only one of the above functions, requiring several incisions for placement of multiple portals to accommodate a suitable number of endoscopic instruments for performing the required functions or necessitating frequent withdrawal and replacement of the individual endoscopic instruments through a single incision. In some instances, an endoscopic instrument may be inserted into the abdomen of the patient and not removed until the procedure is completed. Here, no instrument exchange is required, even though a port is in place.
The majority of laparoscopic ports used are disposable. Reusable, sterilizable ports are available, but have several drawbacks. In order to purchase sufficient reusable ports to accommodate a moderate sized operating room facility several thousands of dollars in capital expenditure is required by the hospital. Known reusable ports are also somewhat difficult to maintain. Rubber seals and valves crack and break with repeated use and sterilization. Maintaining and replacing small seals and parts requiring disassembly of the port is tedious and often results in lost or damaged parts. Also, the trocar portion of the apparatus often becomes dull after several uses. Using a port that is not sharp, or that leaks is frustrating for the surgeon and potentially dangerous to the patient.